Machine tool



Feb. 3, 1942. A. MAURER 2,271,598

MACHINE TOOL Filed March 22, 1940 7 Sheets-Sheet 1 A. MAURER MACHINE TooL Feb. 3, 1942.

Filed March 22, 1940 '7 ShetS-Sheet 2 Feb. 3, 1942.

A. MAURER MACHINE TOOL Filed March 22, 1940 7 sheets-sheet 3 Feb. 3, 1942. A. MAURER 2,271,598

MACHINE Toorl Filed March 22, 1940 v sheets-sheet 4 1761).*3-1942y A, MAURER 2,271,598

MACHINE TOOL l Filed March 22, 1940A '7 Shees-Sheet 5 A--llhIIIIIIIIIIIIIIIIIIIll VIIIIIIIIIII Feb. 3, 1942. A MAURER I' 2,271,598

- A MACHINE TooL I Filed March 22, 1940 7 Sheets- Sheet 6 Feb. 3, 1942. A. MAURER 2,271,598 MACHINE TOOL Filed March 22, 1940 7 sheets-sheet 7 Patented Feb.l 3, 1942 MACHINE TOOL Homburg v. d. Hohe, Ger- I. Antrieb Werner Reimers Albrecht Maurer, Bad many, assigner to P.

K.G., Bad Homburg v. d. Corporation of Germany March 22, 1940, Serial No. 325,425 Germany March 22, 1939 Application In 15 Claims.

This invention relates to machine toolsand has special reference to a lathe or the like.

One important object of the invention is to provide a novel construction of machine tool having means to insure constant cutting speed.

A second important object of the invention is to provide a novel construction of machine tool provided with a speed regulator and having an adjusting device controlling the action of the speed regulator.

With the above and other objects in view, the invention consists in general of certain novel details ofconstruction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings and particularly claimed.

Two forms of the invention are illustrated by way of example in the accompanying drawings, in which Figure 1 is a diagrammatic plan of the rst embodiment; Fig. 1 is a sectional view on the line I'-I of Fig. l;

Fig. 2, a section on the line II-II, of Fig. 1;

Fig. 3, a view of the adjusting device;

Figs. 4 to 7 show the essential parts of the second embodiment as applied to a lathe.

More particularly:

Fig. 4 is a side view,

Fig. 5a plan,

Fig. 6, a view in the direction of the arrow A, of Fig. 4; and

Fig. 7, a section on the line VII-VII, of Fig. 5.

Fig. 8 iis a front view of the gear transmitting the motions of the cross slide to a differential gear and a view of the latter;

Fig. 9, a. vertical section through this gear;

Fig. 10, a partial view, partly in section, on the line X-X, of Fig. 8;

Fig. 11, a top view of the casing containing this gear;

Fig. 12, a front view of the countershaft adjustment and of the differential gear influence thereby;

, Fig. 13, a vertical section of Fig. 12;

Fig. 14, a vertical section on the line )UV- XBL Fig. 4, through the adjusting device;

Fig.` 15, a cross section on the line`XV-XV,

of Fig. 14;

Fig. 16, a horizontal section on the` line XVI-XVI, of Fig. 15;

Fig. 11, a view in the direction of the arrow B, of Fig. 16, and

Fig. 18, a cross section on the line XVIII- XVIII, of Fig. 14.

In the constructional embodiment of the invention shown in Figs. 1 to 3 a motor I drives by Hohe, Germany, a

(ci. sa-29) a coupling 2 the driving shaft 3 of a gear 4 for infinitely variable speed transmission whose driven shaft 5 is connected with a countershaft 6. On the counter shaft 6 three toothed wheels 1, 8 and 9 can be displaced by a rack II actuated by a toothed wheel III and thereby brought into engagement with three toothed wheels l2, I3, I4 which are firmly arranged on a working spindie I5.

The variable speed gear 4 comprises two pairs 'of cone pulleys'IB, I1 which are displaceable on the shafts 3 and 5 and between which a V-belt I8 is provided. For regulation, the spacing of the cone pulleys I6, I1 on the two shafts 3, 5 is adjusted by means of the levers I9 which are actuated by a spindle 20 having two threads and driven by an electromotor 2I through gear wheels 22.

On the cross slide 25 carrying the turning tool 26 and displaceable by a hand wheel 23 and a screw spindle 24 a rule 21 is arranged which can be displaced thereon by a hand wheel 10 and a screw spindle 1I so that a mark 12 connected with the rule 21 can be brought into register with the point of the turning tool 26. The rule 21 is disposed obliquely to the direction of niotion of the cross slide 25 and its effective lower edge 28 ascends in the same direction. At its rear end the edge 28 has a horizontal portion 29. Transversely to the direction of motion of the cross slide 25 the lathe carries a rotatable cone 38 which at its truncated end is extended to form a roller 3l. The cone 30 and the roller 3l possess on their inner surface a helical guide 32 the direction of which corresponds at every point .to that of the edges 28 or 29 of the rule 21, the

rule 21 and the cone 38 being so arranged relative to one another that the edge 28 or 29 of the rule 21 abuts against the guide 32. During displacement of the cross slide 25 in the direction of decreasing diameters the cone 30 is rotated by the rule 21 pressing against the guide 32. At the return of the cross slide 25 a torsion spring 33 insures steady pressure of the guide 32 relative to the'rule 21 and thereby corresponding return motion of the cone 30.

'I'he shaft of the cone 39 carries a gear wheel 34 which drives a. gear wheel 31 connected with a sun wheel 35 of a planetary gear 36. The other sun wheel :a is adjusted through the medium of two bevelgears 39 by a hand wheel 40 which serves for manual adjustment of the cutting speed to be read on a scale 4I.

'Ihe planet center 42 of thev planetary gear 36 is connected with a shaft 43 on which a sun wheel 44 of a second planetary gear 45 is secured. The other sun wheel 45 is driven by bevel gears 41 from the shaft 48 of the toothed wheel I0 of the countershaft adjustment. 'I'he toothed wheel III is adjusted by a crank 49 with which graduations 50 for maximum and minimum cutting speeds are associated that can be attained at the respective countershaft position by the regulatable lathe drive. These graduations 59 move in front oi a stationary scale I for the working diameters and clearly indicate within which cutting speed range these diameters may be Worked.

The planet center 52 of the gear 45 drives a regulating shaft 53 which actuates an adjusting device 54 for the auxiliary motor 2 I. The `spindle 20 carries a pinion 55 which acts upon a gear wheel 55 for effecting the return of the adjusting device 54.

Fig. 3 shows an adjusting device 54. The regulating shaft 53 firmly supports a contact lever 51 and is further provided with two additional contact levers 58, 59 which are loosely disposed thereon, include between them the lever 51 and are pressed together by a spring 60. Contact between the levers 58, 59 and the lever 51 is prevented by a stop pin 5I which is disposed on the gear wheel 55 acting as return member and is thicker than the contact lever 51. 'Ihe contact levers 51, 58, 59 are connected with the auxiliary motor 2| equipped for clockwise and counterclockwise running.

The motions of the shaft 53 represent the combined influence of the manual adjustment 40 of the cutting speed, of the cross feed by the planetary gear 35, and of the countershaft adjustment 49 by the planetary gear 45.

When the variable speed gear 4 is in any position within its range and one of the factors influencing regulation is adjusted, the contact lever 51 makes a certain stroke and touches either the contact on the lever 58 or that on the lever 59, 'according to whether the gear 4 is to run at lowerv or higher speed. In the event that the contact on the lever 51 touchesthe contact of the lever 58 the auxiliary motor 2I effecting the regulation of\y the gear is started in such direcftion that the gear slows down. The return gear 55 then moves Fcounterclockwise and'with the pin 5I attached to it meets the lever 58v and interrupts the contact between the members 51 and 58 whereby the slow speed regulation is completed. l

When the position of the turningtool in the radius is reduced or a slower connecting gear thrown in, each of these operations must be compensated by a corresponding speedingy up of the gear 4. The lever `51 will then maker a return stroke, thereby touching the contact on the le- 55 is pressed against a stationary cam disc 55 coaxially arranged with the return disc 55 and controlling the position of the pin 5I with respect to the return disc 55 so as to providethe requisite relation between the angular strokes of the stop pin 5I and the variations in speed.

In the second embodiment shown in Figs. 4 to 18 the lathe body. is indicated inFig's. 4 to '7 by dot and dash lines.

As in the first embodiment, a motor I drives by a coupling 2 the driving shaft 3 of an innitely variable speed gear 4 whose driven shaft 5 is connected with a countershaft 5 on which 'two toothed wheels 1, 8 can be displaced by a rack II actuated by a toothed wheel III and can toothed wheels I2, I3 which are iirmly secured thus4 be brought into engagement with two toothed wheels I2, 4I3 which are iirmly secured to the working spindle I5.

The variable speed gear 4 is provided again with two pairs of cone pulleys I5, I1 which are displaceable onthe shafts 3, 5` and between which a V-belt I8 is arranged. For regulation, the spacing of the cone pulleys I5, I1 on the two shafts 3, 5 is adjusted by the levers I9 which are actuated by a spindle 28 having two threads n and being driven by an electromotor 2| with the aid of gear wheels 22 and a coupling 13.

In this construction also the differential gear with the sun wheels 35', 38' and the planet center 42' is present, but is formed here as spur gearing, and the same applies to the other difl ferential gear 45' with the sun wheels 44', V45

ver 59, so'that the auxiliary motor 2I of the gear 4 starts t0 eiec't speeding up. This motion, too, lasts until the pin 5I of the gear 55 has reached again the lever 59 and thereby interrupts contact between levers 51 and 59.

In case a regulatable drive is employed in which the course of the speeds depending on the position of the regulator is not such that percentually equal variations of the speed are always associated with equally sized angular motions of the stop pin 5I, the return device may be constructed in the manner shown in Fig. 3.

The stop pin 5I is in this instance not firmly secured to the gear 55 acting as return disc, but is arranged thereon by means of a crank .52 whose pin 53 supports a lever 54 which is displaced relative to the crank 52 and by a spring and the planet 52',

'I'he driving spindle 24' of the cross slide 25' transmits the motions to the sun wheel 35' of the differential gear 35', arranged in a casing 14 A secured to the apron of the lathe, in the following manner: The spindle 24' supports a spur gear 15 in mesh with a spur gear 15 disposed on the casing 14. To the shaft 11 of the gear 15 an arm 18 is attached which at its end supports a spur gear 19. 4In the casing 14 a shaft 80 is firmly arranged one end of which is secured to a shield 8| whilst .the other end thereof extends into a hollow space of a shaft 11 and supports bearings 82 about which the shaft 11.rotates. The shaft has firmly secured thereto a spur gear 83 in mesh with the spur gear 19 which rolls over the spur gear 83 during rotation of Vthe shaft 11.

A hub 84 on which a spur gear 85 is rmly arranged is rotatable about the shaft 80, the

gear 85 being as large as the gear 83 and is The gear 85 has, however, one tooth less than the gear 83 which for instance has sixty teeth against nity-nine of the gear 85.

To the hub 84 a pressure disc 85 is secured between which and the spur gear 85 a hub 81 of a spur gear 88 is loosely mounted. The hub 81 has an in-built friction clutch 89 and is driven by pins or plugs 9| pressed by springs 98 on to the gear 85 and the pressure disc 86. The spur gear 88 engages a rack 92 displaceably disposed in the casing 14 and guided on a bar 93.

The rack 92 is connected by screws with the lower end of a rule 21' the eif'ective edge 28' of lwhich is inclined and extends at its lower end into a horizontal portion 29'. The upper lend of the rule 21' is positioned in a guide 94 secured in the casing 14.

considerably reduced degree tol the gear 88 and by-the latter to the rule 21'.

The rule 21' abuts with its effective edge 28' against a plane curve 95 firmly secured to a shaft Y 98 in the casing 14, which by means of a spur gear 91 transmits the motions to the sun wheel v35', also formed as spur gear, of the differential gear 38'.

In order to permit adjustment of the rule 21',

after the clamping of a tool of different reach, to the position corresponding to the setting of the tool edge a rotary knob 98 is provided on the casing 14, which through the spur gears 99, acts on a spur gear |0| engaging the spur gear 88. During this adjustment the cross slide 25' remains stationary and the gear 88 rotates relative to the gear 85 while the friction of the clutch 89 is overcome. The shaft of the rotary knob 98 supports a drum |02 showing the values of the working diameters, which can be read at a xed zero mark |03.

For adjusting the desired cutting speed a second rotary knob 40', formed in the iirst embodiment as hand wheel, acts through spur gears |04, on the other sun wheel 38' of the diierential gear 38'. The shaft of the knob 40' supports a drum provided with a cutting speed scale 4|', found also in the first embodiment, and with a fixed mark |08 for reading the speed.

The rotations of the sun Wheels 35', 38' are summed up in the motion of the planet center 42 which transmits them through a pair of bevel gears |01 to the shaft 43', also found in the first embodiment,

device for shifting the lconnecting gear wheels 1, 8. As in the rst construction, the toothed wheel I0 is disposed on a shaft 48' which is rotated by a crank 49'. The 'shaft 48 is arranged in a. casing |09 secured to the lathe and s upports a disc ||0 on which at both edges of an arcuate slot scales ||2 for rthe working diameter are provided. -The scales are moved by a fixed scale ||3 for the cutting speed and are visible through a window ||4 in the front wall of the casing |09. The shaft 48' carries a toothed wheel ||5 engaged by a rack ||8 which at its other end is in mesh with the sun wheel 48' of the dierential gear 45'. The planet center 52' thereof supports a sprocket wheel from which a chain ||8 leads as drive to an adjusting device for the speed regulator,which acts as preselector and actuates the auxiliary motor 2|.

This adjusting device is positioned in a casing H9. The chain ||8 runs over a sprocket wheel mounted on'a countershaft |2.| in

' the casing ||9 and supporting a spur gear |22 within the casing. The spur gear |22 drives -through a spur gear |23 a hollow shaft |28 distation within the shaft by a flap |38 secured thereto and disposed in a longitudinal slot |31 of the hollow shaft |28. The rotatable arm |29 whence they are transmitted through a pair of bevel gears |08 to the sun wheel 44 of the differential gear 45.V

The other sun wheel 48' is acted upon by the embraces the hollow shaft |28 in cliplike fashion and has a pin |38 which is connected with the flap |38 projectingfrom the slot |31 by a link |39.V Rotations of the varm |29 about its axis cause a displacement of the pin |38 in thedirection of the axis of the hollow shaft |28 and thereby a displacement of the shaft in the hollow shaft |28.

on its end projecting from the houow sham;

|28 the shaft |35 is provided with a member |4| which is rotatable o n the shaft |35 and fixed in axial direction by means of adjusting rings |40. Rotation of the member |4| relative to the casing H9. are prevented, since it is guided with a semicylindrical recess on a cylindrical member |42 rotatably disposed relative to an axis parallel with the hollow shaft |28 in the insertion |21. The member |4| retains therefore its position during rotation of the shaft |35 while cooperating inall longitudinal disfplacementsl thereof. In the semicylindrical recess of the member |4| a pin |43 is provided which engages a helical groove |44 of the member |42, the latter being rotated by displacement of the pin |43. To the member |42 a reversible switch |48 is attached by means of a bow |45, from whose three contacts three conductors |41 lead to the auxiliary motor 2|. v

On the insertion |21 of the casing H9, coaxially with the hollow shaft |28, a worrn wheel |49 is mounted in a ball bearing |48, which engages a worm |50 vertically disposed thereto on the shaft of which a sprocket wheel |5| is 'arranged outside the casing H9. From the sprocket |5| a chain |52 leads to a sprocket wheel |53 on the spindle 20. i

'Ihe worm wheel |49 has a lateral circular running face |54 with a depression |55. The roller |33 abuts against this running face |54 and in the zero position of the adjusting device engages the depression |55. Each variation of an adjusting factor causes-a rotation of the planet member 52 of the differential gear which finds expression in a rotation of the hollow shaftv |28 whereby the arm |29 is rotated out `of its zero position. In

case of smaller motions of the arm |29 the roller |33 remains in engagementwith the depression |55, but during larger motions it enters upon the running face |54 and rolls thereon. In either case the head |30 is moved thereby, and this motion is connected with a displacement of the pin |38, which is transmitted to the shaft |35 whose displacement is converted into a rotation of themember |42 whereby the switch |48 is reversed and starts the auxiliary motor 2| which regulates the variable speed gear 4 as required. The worm gear |49, causesthe depression |55 to follow the arm |29 until the head |30 is in zero position again, that is, in a plane running through the axis of the hollow shaft |28, whereby also the shaft |35 and the switch |48 are moved into zero position and regulation is completed after th; algjixulsted cutting speed hasV been attained.

1. In a machinetool, particularly a lathe or cutting-off machine, a speed regulator, an adjusting device constituting a preselector for the speed regulator, means for driving the speed regulator, a cutting tool movable over a predetermined path, and means for operatively connectf -ing the cutting toolto the speed regulator including differential gfaring controlled by the ad- Justing device whereby to insure uniformity of cutting speed 'so that percentually equal variaequally-sized adjusting paths of the device, which bring about percentually equal speed variations inversely corresponding to the variations in working diameter, all factors influencing the adjusting device for the cutting speed and including adjustment of the cutting speed and variation of working diameters and of connecting gears acting separately, by kmeans of said differential gears, upon the adjusting device constituting the preselector and driving the speed regulator by said regulator driving means.

` 2. In a machine tool according to claim 1 an adjusting device driven by the cross feed, a speed regulator control by the adjusting device, manual means for adjusting the desired cutting speed and differential gears by means of which the cross feed and the manual adjusting means act upon the adjusting device.

3. In a machine tool according to claim 1 connecting gearings, adjusting means therefor and a differential gear by means of which the adjusting means act upon the adjusting device.

4. In a machine tool according to claim 1 a regulating shaft for controlling the adjusting device for the speed regulator, a planetary gear through the sun wheels of which the manual means for adjusting cutting speed and the cross feed act upon a shaft connected with the planet center of the gear and driving a sun wheel of a second planetary gear the other sun wheel of which is controlled by the countershaft adjustment and the planet center thereof is connected with the regulating shaft.

5. In a machine `tool according to claim l, a i

rule having an ascending effective edge, a cross slide for displacing said rule and a curviform guide acted upon by the rule during its displaceguide on the cone and thereby turns the cone and the differential gear member according to the l cross feed.

7. A machine tool according to claim 1, in which a rule positioned and ascending obliquely to its direction of motion is positivelyl moved by the cross slide directly proportionally thereto and bears against a cone, operatively connected with a member of a differential gear acting on the shaft to which a sun wheel of the second planetary gear is secured, in `such manner that during its displacement it presses against a helical guide on the cone and thereby turns the cone and the differential gear member according to the cross feed, and in which the effective edge of the rule has a rear horizontal portion and the cone is truncated and extends into a roller.

8. A machine tool according to claim 1, comrising a speed regulator, an auxiliary motor therefor, a shaft regulating the speed adjusting device, acontact lever attached to said shaft, two additional contact levers loosely arranged on said shaft and pressed together by a spring, said first contact lever being movably disposed between said two additional levers, a return means, a stop pin connected with the return means moved by 2,271,598 "tions of the working diameter are associated with the speed regulating means and engaging between said loosely disposed contact levers and interrupting the contact between the contact lever firmly attached to the shaft and a loosely disposed contact le'ver, said stop pin having such thickness that the contact lever firmly attached to the shaft can stand between said two loosely disposed contact levers without touching them.

9. A machine tool according to claim 1, comprising a speed regulator, an auxiliary motor therefor, a shaft regulating the speed adjusting device, a contact lever attached to said shaft, two additional contact levers loosely arranged on said shaft and pressed together by a spring, said flrst contact lever beingmovably disposed between said two additional levers, a return means, a stop pin connected with the return means moved by the speed regulating means and engaging between said loosely disposed contact levers and interrupting the contact between the contact lever firmly attached to the shaft and a loosely disposed contact lever, said stop pin having such thickness that the contact lever firmly attached to the shaft can stand between said two loosely disposed contact levers without touching them, and in which the stop pin is movably disposed on a crank of the return meansand is additionallycontrolled as to its position relative to said return means by a stationary cam disc.

10. A machine tool according to claim l, in which the rule is displaced in its plane and acts upon a curve positioned in this plane and movable about a shaft arranged vertically thereto, the rotations of said curve serving for adjusting the differential gear member.

11. A machine tool according to claim' 1, in which the rule is displaced in its plane and acts upon a curve positioned in this plane and movable about a shaft arranged vertically thereto, the rotations of said curve serving for adjusting the differential gear member and in which the rotations of the driving spindle of the cross slide are transmitted by a reducing gear to a rack vertically disposed relative to the spindle and displacing the rule.

.12. A machine tool according to claim 1, in which the rule is displaced in its plane and acts upon a curve positioned in this plane and movable about a shaft arranged vertically thereto, the rotations of said curve serving for adjusting the differential gear member and in which in the drive of the rule a friction clutch is provided and also means for adjusting the rule to a Workingdiameter read on a scale, said means acting on a gearmember between the friction clutch and the rule and permitting adjustment ofv the rule to a working diameter corresponding to the position of the clamped tool while overcoming the friction of the clutch.

13. A machine tool according to claim 1, in which an auxiliary electric motor for the speed regulator is provided and the adjusting device.

about the hollow shaft and driven by the speed regulator, said guide having a depression engaged by the roller when the guide and head are in zero position so that relative rotation of the circular guide and arm causes rotation of the head, emergence of the roller from the depression and a corresponding displacement of the pin and motion of the switch. V

14. A machine tool according to claim 1, in which an auxiliary electric motor for the speed regulator is provided and the adjusting device comprises a hollow shaft adjustable by the elements determining cutting speed, said hollow shaft having an arm whose lrotatable head is operatively connected with a pin, non-rotatably yet longitudinally displaceably in the hollow shaft, in such manner that rotations of the headabout its axis cause ldisplacexznents oi the pin through which a switch for starting and stopping the auxiliary motor is moved and that the head, positioned in a plane passing through the axis of the hollow shaft when in zero position, carries a rollerl bearing against a circular guide rotatable about the hollow shaft and driven by the speed regulato said guide having a depression engaged by the roller when the guide andv head are in zero position so that relative rotation of the circular guide and arm causes rotation o! the head, emergence of the roller from the depression and a corresponding displacement t of the pin and motion or the switch and in which the head and its supporting arm are rotatable about the axis thereof disposed vertically to the axis of the hollow shaft and the circular guide forms a wheel provided in its side facing the head the head. positioned in a with a running face having a depression.

15. A machine tool according to claim 1, in which an auxiliary electric motor for the speed regulator is provided and the adjusting device comprises a hollow shaft adjustable by the elements determining cutting speed, said hollow shaft having an arm whose rotatable head is operatively connected with a pin, non-rotatably yet longitudinally displaceably disposed inthe hollow shaft. in such manner that rotations of the head about its axis cause displacements of the pin through which a switch for starting and stopping the auxiliary motor is moved and that the axis of the hollow shaft when in zero position. carries a roller bearing against a circular about the hollow shaft and position so that relative roguide and arm causes rotaof the roller from and head are in yzero tation of the circular tion of the head, emergence the depression and a corresponding displacement switch.

AT BRECHT MAURER.

plane passing through 

